Electric switch.



No. 797,252. PATENTED AUG.15, 1905. M V. AYRES & D. E. HENNESWI.

ELECTRIC SWITCH.

APPLIUATION FILED FEB. 9, 1905.

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MILAN V. AYRES, OF NEW TON, AND DANIEL E. HENNESSY, OF EVEHETTIT, MASSACHUSETTS.

lEtEtlTfHlC SWIFM H II.

Specification of Letters Patent.

Patented Aug". 15, 190%..

Application filed February 9, 1905. Serial No. 244,884.

To (bl/7 whom, it may cancer-1t:

Be it known that we, MILAN V. AYR'Es, a resident of Newton, and DANIEL E. HEN- NEssY, a resident of Everett, in the county of lvliddlesex and State of Massach usetts, citizens of the United States, have invented new and useful Improvements in Electric Switches, of which the following is a specification.

Our invention relates to the construction of automatic electric switches, and is espe cially designed for use in connection with overhead trolley railway systems wherein our said improvements may be utilized as component parts of any apparatus requiring automatic electric switching devices. Our improved switch is, for instance, adapted to form part of automatic block-signal systems; but it should be borne in mind that the im provements herein described and claimed are doubtless susceptible of use in other connections and electromechanical associations.

In the drawings hereto annexed, which illustrate sundry embodiments of our inven tion and improvements, Figure 1 is a side elevation of an automatic electric switch. Fig. 2 is a side elevation of a modified form of the same. Fig. 3 shows in vertical cross-section a detail of the construction shown in Fig. 1. Fig. 4 illustrates one mode of application of the apparatus of Fig. 1 to an overhead-trolley wire, and Figs. 5 and 6, shown in plan view diagrammatically, a mode of application of the electric switch exhibited in detail in Figs. 1. or 2.

Heretofore there have been contrived several methods of automatic electric switch or signaling operation in which the passage of a trolley along the trolley-wire is utilized to actuate the switch or other signaling device. Where actual mechanical contact between the trolley and the switch-operating piece has been resorted to, diflieulties have been encountered, especially under high-speed conditions. At high speeds, such as are employed in long-distance and cross-country railroads, the presence of a mechanical obstacle to the passage of the trolley is likely to result either in throwing the trolley off the wire or in breaking or in otherwise damaging the contactpiece. Furthermore, in nearly all signaling systems capable of use on electric roads electromagnets are relied upon to produce the necessary mechanical effects, and as an electromagnet requires an appreciable time to become energized the swiftness with which the trolley passes a contact obstacle or runs over a contact-surface defeats the proper action of such electromechanical contrivances.

The devices illustrated in the drawings which embody our inventions and improvements eliminate the above-enumerated disadvantages and furnish an electric switch which when used as an adjunct to an overhead trolley system is sure to operate no matter what may be the speed. of the electric car and which is, moreover, cheap and sim ple to make and very unlikely to get out of order.

Referring to Fig. l, T is the trolley-wire, shown in cross-section, and S a support along side the trolley-wire, which support may be itself a wire or possibly a fixture attached to a post. Supported at one end on the trolleywire T and at the other on the support S is a bridge B, which consists, preferably, of a piece of light iron pipe. A U-shaped tube A, which may be, say, another piece of iron pipe of small inside diameter for instance, one eighth to one-fourth of an inch-has its two arms A and A passed through holes in the bridge-pipe B and secured at the upper side to the cups or chambers C C. The U-shaped tube A is filled with mercury, so that when the two ends of the tube are level the mercury rises up to or near the juncture of the branches A A with the receptacles C C. In the example shown in Fig. 1 the receptacle C performs only the function of an air-chant ber, whereas the receptacle G contains the electric contact devices, which will be better understood by reference to Fig. 3. A cap I), which may be of wood, glass, porcelain, or other suitable insulating material, is inserted in the top of the receptacle 0. Through this cap there passes the pin E, which may be of iron and which extends down through the interior of the receptacle C to a point close to the surface of the mercury M in the branch A of the U-shaped tube. For purposes presently to be indicated we prefer to envelop the lower portion of the pin E in a bath 0, of oil, which. partially fills the receptacle 0. At the binding-post G is attached a wire H, and to the outer end of the pin E is secured the wire F, these wires being part of the circuit which is controlled by the operation of the automatic switch. It will be seen. that if the device illustrated in Fig. 1 be tilted in the plane occupied by the U-shapcd tube A the mercury M, Fig. 3, will rise or fall in the branch A according to which way the tube is tilted. If the branch A is raised, the mercury M will rise until it makes contact with the pin E, and when the level of the tube is restored to its normal condition this contact will be broken.

In Figs. 5 and 6 there is illustrated a mode of attachment of the automatic electric switch illustrated in Figs. 1 and 3. In these figures, as before, T is the trolley-wire, and P P P P the posts by which the trolleywire is held suspended either by brackets, as indicated in Fig. 6, or by suspension-wires, as indicated in Fig. 5. Between the suspensionwires and posts P P there is stretched a wire S, Fig. 5, and guy-wires S S may be attached to hold the wire S in the proper state of tension. At about the middle of the span of the trolley-wire T the automatic electric switch is placed, its bridge B resting at one end upon the the trolley-wire T and at the other upon the support-wire S. The wires F H may be led to one of the posts, as P, and thence to whatever electrical apparatus the constructor pleases. In Fig. 6 the arrangement is the same as in Fig. 5, except that the suspension of the trolley-wire is from brackets. By placing the automatic switch in suspension at point midway between the trolleywire supports the fullest possible range of motion is given to the switch itself. It is well known that no matter how tightly a trolley-wire may be stretched it must necessarily rise when the trolley passes along and under it, and the effect of this lifting by the trolley is felt for many feet both in advance and in the rear of the trolley itself. Therefore as the trolley comes along the wire T it begins to lift the trolley-wire-supported end of the bridge B long before the trolley itself reaches the spot where the bridge B is supported and as it leaves the bridge gradually allows it to descend to its normal position. Further, as the other end of the bridge B rests on the supporting-wire S, which partakes, if at all, but little of the lifting effect of the trolley, the bridge B and its attached U-shaped tube A are tilted whenever a car passes, and, as has been seen, when this U tube is tilted the mercury contained therein makes electric contact with the pin E within the receptacle C. It may be that the voltage in the circuit thus closed by the two contact-piecesnamely, the rod E and the upper part of the mercury Mis high and that unless provision were adapted against it sparking would result whenever the two contact-pieces broke connection. To this end we recommend the introduction of the oil-bath O, which will prevent the injurious effects of sparking aforesaid.

Other forms of automatic electric switch comprising a bridge or carrier and contactpieces whereof one is on the bridge or carrier and the other controlled byabody movable on the carrier may readilybe contrived. For instance, in. Fig. 2 we show such an alternative form, wherein the tube A is straight and con stitutes not only the fluid-receptacle, but the bridge between the trolley-wire T and supporting-wire S. Ordinary pipe Ts C C may be employed in place of the cups C C of Fig. 1. A small quantity of mercury is introduced into the-tube A and when the tube is tilted will flow toward one end or the other, and when the mercury accumulates in the end nearest the support S contact between jthe pin E and the mercury will result, as beore.

Another situation in which our automatic electric switch may be found useful is indi cated in Fig. 4, where the switch itself is mounted upon and above the trolley-wire T and held by guy-wires, the U-tube A being in this instance in a plane parallel, or nearly so, to the wire T. In this case contact-pieces may be carried by the fluid-receptacle at both of its ends that is to say, both the cups C and C. In this situation, according to the direction in which the trolley passes, the contact at C or C will be closed first and the contact at C or 0 later. The skilled electrical engineer can easily imagine or contrive apparatus to operate selectively according to the order in which these circuit-closures are made, and thus to distinguish by signals between the passage of a car in one direction from passage in the other.

We have purposely refrained from describing any special electrical circuits or apparatus to be operated or controlled by our improved automatic electric switch, for the reason that in the operation of such devices there may be very many uses to which they may advantageously be put. We suggest, however, that for operating various kinds of railway block-signal systems, especially in connection with trolley-roads, this improved switch will demonstrate its efficiency. In actual practice it has proved extremely quick in operation, sensitive to slight tilting of the switch itself, and by reason of the fact that the passing trolley communicates its lifting effect to the switch for a considerable time the contact closed in the switch remains closed long enough to actuate any kind of electric or electromagnetic apparatus. Moreover, the improved switch is devoid of eX- posed parts, which in the situation in which such things are necessarily used are very likely to get out of order. It is, moreover,

switchcomprising a carrier between said support and the trolley-wire, a body on and movable in relation to said carrier and adapted so to move in response to tiltingthereof, and a circuit-closer whereof contact is controlled by the position of the movable body on the carrier.

2. The combination with a trolley-wire, of an electric switch comprising a fluid-receptacle, a fluid therein. and a pair of contacts, one moved by the fluid, the other on the fluid-receptacle, to make and break as the receptacle is tilted and connections between the trolley-Wire and the said switch.

3. The combination with a trolley-wire of an electric switch, comprising a :l'luid-receptacle having two branches, a fluid therein and a pair of contacts one moved by one branch of the receptacle, the other by the fluid in. that branch, to make and break as the receptacle is tilted and connections between the trolley-wire and the said switch.

a. The combination with a trolley-wire of an electric switch, comprising a lJ-tube, mercury in the tube, a chamber at one end of the U having a contact-piece to touch the mercury as the tube is tilted, and connections between the trolley-wire and said switch.

5. The combination with a trolley-wire of an electric switch, comprising a fluid-receptacle, a fluid therein, and a pair of contacts one moved by the fluid, the other by the re ceptacle, to make and break as the receptacle is tilted, and connections between the trolleywire and the said switch which join the wire at a point between trolley-wire supports.

6. The combination with a trolley-wire of an electric switch comprising a fluid-receptacle having two branches, a fluid therein and a pair of contacts one moved by one branch of the receptacle, the other by the fluid in that branch to make and break as the receptacle is tilted, and connections between the trolley-wire and the said switch which join the wire at a point between trol ley-wire supports.

7. The combination. with. a trolley-ire oi. an electric switch comprising a tJ-tu be, mercury in the tube, a chamber at one end of the U having a contact-piece to touch. the inercury as the tube is tilted, and connections between the trolley-wire and the said switch. which join the wire at a point between the trol ley-w i re sup ports.

8. The combination with a trolley-wire ol a su )porting-wire at one side of the trolleywire and an electric switch comprising a fluidreceptacle, a fluid therein, and a pair oi contacts one moved by the fluid, the other by the receptacle, to make and break as the receptacle is tilted, the said switch suspended between. the trolley-wire and the supporting-wire.

9. The combination with. a trolley-wire, of a supporting-wire at one side of the trolleywire and an electric switch comprising a fluidreceptacle having two branches, at fluid therein and a pair of contacts, one moved by one branch of the receptacle, the other by the fluid in that branch to make and. break as the receptacle is tilted, the said switch suspended between the trolley-wire and the stmportingwire.

10. The combination with a trolley-wire of a supperting-wire at one side of the trolley wire, and an electric switch comprising a U- tube, mercury in the tube, a chamber at one end of the U having a contact-piece to touch the mercury as the tube is tilted, the said switch suspended between the trolley-wire and the supporting-wire.

Signed by us at Boston, Sui'lolk county, Massachusetts, this 3d. day of February, 1905.

MILAN V. AYRES. DANIEL E. HENNESSY. l Vitnesses: 7

CHARLES D. Woonnnnnv, Josnrn T. BRENNAN. 

